thromboxane-b2 and Proteinuria

Serum creatinine, immunoreactive serum and urine beta-2-microglobulin, plasma and urine thromboglobulin, plasma thromboxane-B2 levels and daily protein excretion were determinated in 61 insulin treated diabetic patients, comparing the different patient groups (complication free, nephropathy without azotaemia and nephropathy with azotaemia) with the control subjects. In the groups of all diabetic patients plasma and urine beta-thromboglobulin and plasma thromboxane-B2 levels were higher that in the controls. There was a positive significant correlation between urine beta-thromboglobulin and beta-2-microglobulin in the group without complication, and between the plasma beta thromboglobulin and beta-2-microglobulin, and plasma beta thromboglobulin and thromboxane levels in the diabetic group with azotaemia. In contradiction to some previous assumptions, the increased level of plasma beta-thromboglobulin reflects a real platelet hyperactivation also in patients with diabetic nephropathy. At the same time urine beta-thromboglobulin also increases. Determination of urine beta-thromboglobulin is more simple with less possibility of methodological error.

Topics: beta 2-Microglobulin; beta-Thromboglobulin; Blood Platelets; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Humans; Proteinuria; Thromboxane B2

High urinary Prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) levels have been reported in lupus nephritis (LN). Captopril diminishes proteinuria and improves glomerular filtration rate (GFR), and may have effect on immune function. We evaluate captopril effect on urinary PGE2, and TxB2.. Eighteen LN patients were randomly assigned to two groups. Group 1 received only prednisone plus cyclophosphamide. Group 2 received also captopril. Serum creatinine, GFR, RPF, urinary proteins, PGE2 and TxB2, were assessed.. There were no differences between the initial and final assessments in Group 1. Group 2 showed a significant decrement in proteinuria (p=0.003) and serum creatinine (p=0.01) at the end of the study. PGE2 decreased significantly when compared with the initial value (p=0.02).. Captopril plus usual treatment, improved serum creatinine and decreased proteinuria in parallel with prostaglandin E2 reduction. This effect is not related to changes in GFR or RPF. Captopril may have an immunomodulatory effect on local inflammatory processes in lupus nephritis.

Topics: Adolescent; Adult; Captopril; Cyclophosphamide; Dinoprostone; Humans; Lupus Nephritis; Prednisolone; Proteinuria; Thromboxane B2

Systemic lupus erythematosus (SLE) is an autoimmune disease, characterized by nephritis, in which mortality is largely influenced by the severity of renal involvement. As there are evidences that thromboxane (TX)A2 plays an important role in the pathogenesis of lupus nephritis, we decided to assess the effects of long-term suppression of TXA2 synthesis on the progression of the disease, by designing a study of TXA2-synthase inhibition having adequate size to detect an effect on mortality as the primary end-point. Thus, we randomized 362 NZBxNZW mice (11-week-old at entry) to one of the following treatments: a TXA2 synthase inhibitor, FCE 22178 (300 mg/kg daily), saline or cyclophosphamide (5 mg/mouse weekly x 4 weeks) used as reference treatment. The TXA2 synthase inhibitor suppressed TXA2 biosynthesis, as reflected by urinary TXB2 and 2,3-dinor-TXB2 excretion (by 78% and 90%, respectively) and significantly reduced mortality (death rate: 34% vs. 61% in controls, at 37 weeks, P < 0.01). A significant reduction in proteinuria (9 +/- 1.6 vs. 17.3 +/- 2.4 mg/24 hr in FCE 22178 vs. saline, P < 0.01) and glomerular lesions was observed up to 30 weeks but not at 37 weeks. In contrast, cyclophosphamide prevented the development of proteinuria and histologic lesions, and reduced mortality to 8% at 37 weeks. Renal plasma flow and glomerular filtration rate were lower (by 29% and 52%, respectively) in 37-week-old as compared to young NZBxNZW mice. These parameters were further depressed by cyclophosphamide (by 48% and 45% vs. age-matched controls, respectively, P < 0.01) but were not altered significantly by FCE 22178.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cyclophosphamide; Disease Models, Animal; Female; Fluorescent Antibody Technique; Glomerular Filtration Rate; Imidazoles; Lupus Nephritis; Mice; Mice, Inbred NZB; Naphthalenes; Proteinuria; Survival Rate; Thromboxane B2; Thromboxane-A Synthase

Dietary supplementation with n-3 polyunsaturated fatty acids (n-3 PUFA) has been shown to reduce proteinuria in experimental models of renal diseases, but their potential role in the treatment of human renal disease is unknown. We administered n-3 PUFA in the form of triglycerides [with eicosapentaenoic (EPA)+docosahexaenoic (DHA) = 3 g/day into 4 patients] and of ethyl esters (EPA+DHA = 7.7 g/day) into 10 patients (one patient twice) with chronic glomerular disease (membranous glomerulonephritis and focal glomerular sclerosis), all diagnosed histologically. Serum albumin was > 2.4 g/dl and serum creatinine < 2.5 mg/dl in all patients. Treatment was given for periods of six weeks, followed by a prolonged follow-up for 27 weeks in 10 cases. Dietary supplementation with n-3 PUFA caused the expected reduction in platelet generation of thromboxane B2 (mean +/- SEM, from 490 +/- 70 ng/ml at baseline, to 342 +/- 147 ng/ml at 6 weeks, P < 0.05) of serum triglycerides (from 236 +/- 60 to 170 +/- 43, P < 0.01), and a prolongation of the bleeding time (from 5.8 +/- 0.4 min to 7.7 +/- 0.4 min, P < 0.01) in patients treated with ethyl esters. A modest but significant reduction in serum total cholesterol was noticed (from 275 +/- 27 to 252 +/- 24 mg/dl).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Aged, 80 and over; Blood Pressure; Cholesterol; Chronic Disease; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Female; Glomerulonephritis, Membranous; Glomerulosclerosis, Focal Segmental; Humans; Male; Middle Aged; Proteinuria; Thromboxane B2

Studies of nondiabetic renal disease suggest that thromboxane may be an important mediator of abnormal renal function. The role of thromboxane in diabetic nephropathy is not fully understood. We measured in a double-blind, randomized, placebo-controlled crossover study the effect of a thromboxane synthase inhibitor (FCE 22178, 400 mg two or three times per day) on urinary excretion of thromboxane B2 and 6-keto-prostaglandin F1 alpha, glomerular filtration rate (measured as clearance of polyfructosan), effective renal plasma flow (clearance of para-aminohippuric acid), fractional clearances of albumin and immunoglobin G and the reabsorption rate of beta 2-microglobulin in 15 patients with type 1 (insulin-dependent) diabetic nephropathy. In seven additional patients, the effect of the thromboxane synthase inhibitor given as 400 mg twice per day was compared with that of the thromboxane synthase inhibitor given as 400 mg three times per day. FCE 22178 administration caused a significant inhibition in the excretion of urinary thromboxane B2 and 2,3-dinor-thromboxane B2 compared with placebo (12.3 +/- 2.1 vs 24.6 +/- 5.1 ng/gm creatinine, p = 0.006, and 78.5 +/- 20.3 vs 335.5 +/- 84.1 ng/gm creatinine, p = 0.004, respectively) without any compensatory increase of 6-keto- prostaglandin F1 alpha or 2,3-dinor-6-keto-prostaglandin F1 alpha that reflect prostacyclin I2 biosynthesis. Glomerular filtration rate, effective renal plasma flow, renal vascular resistance, and filtration fraction were not significantly different after placebo or thromboxane synthase inhibitor treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Blood Pressure; Creatinine; Diabetic Nephropathies; Double-Blind Method; Drug Administration Schedule; Electrolytes; Female; Glomerular Filtration Rate; Humans; Imidazoles; Immunoglobulin G; Kidney; Male; Middle Aged; Naphthalenes; Proteinuria; Renal Circulation; Thromboxane B2; Thromboxane-A Synthase; Urea

Peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear transcription factor, modulates vascular responses to angiotensin II (AII) or thromboxane A(2) (TxA(2)) via regulation of their gene/receptor. Increased vasoconstriction and deteriorating renal function in glycerol-induced acute renal failure (ARF) may be attributed to down-regulation of PPARgamma. In this study, we investigated the effect of ciglitazone (CG), a PPARgamma inducer, on AII and TxA(2) production and activity in glycerol-induced ARF. Vascular responses to AII or 9,11-dideoxy-11alpha,9alpha-epoxymethano prostaglandin F(2alpha) (U46619), a TxA(2) mimetic, were determined in preglomerular vessels following induction of ARF with glycerol. Renal damage and function were assessed in CG-treated (9 nmol/kg for 21 days) rats. PPARgamma protein expression and activity, which were significantly lower in ARF rats, were enhanced by CG (26 and 30%). CG also increased PPARgamma mRNA by 67 +/- 6%, which was reduced in ARF. In ARF, there was significant tubular necrosis and apoptosis, a 5-fold increase in proteinuria and a 2-fold enhancement in vasoconstriction to AII and U46619. CG reduced proteinuria (49 +/- 3%), enhanced Na(+) (124 +/- 35%) and creatinine excretion (92 +/- 25%), markedly diminished tubular necrosis, and reduced ARF-induced increase in AII (40 +/- 3%) and TxA(2) (39 +/- 2%) production, the attending increase in vasoconstriction to AII (36 +/- 2%) and U46619 (50 +/- 11%), and the increase in angiotensin receptor-1 (AT(1)) (23 +/- 3%) or thromboxane prostaglandin (TP) receptor (13 +/- 1%). CG reduced free radical generation by 55 +/- 14% while elevating nitrite excretion (65 +/- 13%). Our results suggest that enhanced activity of AII and TxA(2), increased AT(1) or TP receptor expression, and renal injury in glycerol-induced ARF are consequent to down-regulation of PPARgamma gene. CG ameliorated glycerol-induced effects through maintaining PPARgamma gene.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Acute Kidney Injury; Angiotensin II; Animals; Creatinine; Dinoprost; Gene Expression; Glycerol; Hypoglycemic Agents; Kidney Glomerulus; Male; Nitric Oxide; Nitrites; PPAR gamma; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptors, Thromboxane A2, Prostaglandin H2; Renal Artery; Sodium; Thiazolidinediones; Thromboxane A2; Thromboxane B2; Vasoconstriction

The aims of the present study were to analyse the effects of an oral daily dose (10 mg/kg) of the dietary flavonoid quercetin for five weeks in two-kidney, one-clip (2K1C) Goldblatt (GB) hypertensive rats. The evolution of systolic blood pressure was followed by weekly measurements, and morphological variables, proteinuria, plasma nitrates plus nitrites (NOx) and thiobarbituric acid reactive substances (TBARS), liver oxidative stress markers and endothelial function were determined at the end of the experimental period. Quercetin treatment reduced systolic blood pressure of GB rats, producing no effect in control animals. It also reduced cardiac hypertrophy and proteinuria developed in GB hypertensive rats. Decreased endothelium-dependent relaxation to acetylcholine of aortic rings from GB rats was improved by chronic quercetin treatment, as well as increased endothelium-dependent vasoconstrictor response to acetylcholine and overproduction of TXB2 by aortic vessels of GB rats, being without effect in normotensive animals. Increased plasma NOx and TBARS, and decreased liver total glutathione (GSH) levels and glutathione peroxidase (GPX) activity were observed in GB hypertensive rats compared to the control animals. Normalisation of plasma NOx and TBARS concentrations and improvement of the antioxidant defences system in liver accompanied the antihypertensive effect of quercetin. We conclude that chronic oral treatment with quercetin shows both antihypertensive and antioxidant effects in this model of renovascular hypertension.

Topics: Animals; Antioxidants; Aorta; Blood Pressure; Body Weight; Diet; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelium, Vascular; Glutathione; Glutathione Peroxidase; Hypertension, Renovascular; Kidney; Liver; Male; Nitrates; Nitrites; Organ Size; Oxidative Stress; Potassium Chloride; Proteinuria; Quercetin; Rats; Thiobarbituric Acid Reactive Substances; Thromboxane B2; Time Factors

To study the influence of single leaf Asarum himalaicum on the renal function of rabbits.. Rabbits were divided into three groups. Asarum himalaicum, Asarum heterotropoides and normal saline were intravenously administered to the rabbits of one group respectively. The urine volume per minute, urine pH, urine glucose, protein and red blood cells, BUN, SCr, TXB2, 6-keto-PGF1alpha, TXB2/6-keto-PGF1alpha, endothelin, p-aminohippuric acid clearance rate and phenolsulfonphthalein excretion rate were tested before and after the administration.. A certain dosage of single leaf Asarum himalaicum caused acute renal failure in rabbits. The indices tested were significantly different between rabbits administered Asarum himalaicum and normal saline. As compared with the rabbits administered Asarum heterotropoides, the results of indices tested decreased, but without statistical significance, except for SCr.. The single leaf Asarum himalaicum can cause renal damage to rabbits. Its renal toxicity is lower that that of Asarum heterotropoides.

Topics: Animals; Asarum; Blood Urea Nitrogen; Endothelins; Female; Glucose; Kidney; Kidney Function Tests; Male; Phenolsulfonphthalein; Plant Leaves; Plant Preparations; Proteinuria; Rabbits; Random Allocation; Species Specificity; Thromboxane B2

Recent studies implicate of reactive oxygen species (ROS) in hypertension; however, whether reactive oxygen species promote hypertensive derangements is not fully clear. We thus investigated the effects of an antioxidant, N-acetyl-L-cysteine, on hypertensive Dahl salt-sensitive rats. High-salt intake for 4 weeks markedly elevated systolic arterial pressure, urinary excretion of protein, 8-isoprostane, and H(2)O(2), and the enzyme activity of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase along with the elevated expression of its subunits gp91phox and p47phox at the levels of mRNA and protein. Supplement with N-acetyl-L-cysteine reduced the increase in systolic arterial pressure and counteracted the elevation of urinary excretion of protein, 8-isoprostane, and H(2)O(2), and the increases in NADPH oxidase activity/expression in high-salt-loaded Dahl salt-sensitive rats. N-acetyl-L-cysteine supplement ameliorated plasma and urinary levels of thromboxane B(2) (an end metabolite of thromboxane A(2)), associated with improvement of both the abnormal contraction and the impaired nitric oxide-dependent relaxation in renal arteries. These results revealed that oxidative stress mediates hypertensive changes in Dahl salt-sensitive rats, because thiol antioxidant N-acetyl-L-cysteine attenuated the augmentation of local ROS production by diminishing the elevation of NADPH oxidase expression and ameliorated renal/vascular hypertensive changes.

Topics: Acetylcholine; Acetylcysteine; Animals; Antioxidants; Blood Pressure; Dinoprost; Endothelium, Vascular; Hydrogen Peroxide; Hypertension; Kidney Glomerulus; Male; NADPH Oxidases; Oxidative Stress; Proteinuria; Rats; Rats, Inbred Dahl; Sodium Chloride; Superoxides; Thromboxane B2; Up-Regulation

In this study we investigated the role of a mixture of n-6/n-3 essential fatty acids, in the cyclosporine model nephrotoxicity. Administration of cyclosporine in rats decreased creatinine clearance and provoked body weight loss, but it did not induce proteinuria and did not alter the urine volume. These changes were associated with decreased urinary ratios of prostaglandin E/thromboxane B and prostaglandin I/thromboxane B excretions. Light microscopic sections showed that 100% of the animals were affected by histological tubular lesions on their kidneys. Administration of cyclosporine to animals fed for 3 months on standard chow containing a mixture of n - 6/n - 3 essential fatty acids, restored creatinine clearance, augmented urine volume and prevented body weight loss. The improvement of renal function was accompanied by increased urinary ratios of prostaglandin E/thromboxane B and prostaglandin I/thromboxane B excretions. Light microscopic sections showed that only 40% of the animals demonstrated histological tubular lesions, of minor importance, to their kidneys. Our results suggest that the metabolites of arachidonic acid can play important role in the development of cyclosporine-nephrotoxicity because they increase the levels of thromboxane A and that the enchanced synthesis of prostaglandins (E) and (I) induced by a mixture of n - 6/n - 3 essential fatty acids, could play a beneficial role in the prevention of this renal dysfunction.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Cyclosporine; Dietary Fats, Unsaturated; Dinoprostone; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Female; Kidney; Kidney Diseases; Prostaglandins I; Proteinuria; Rats; Rats, Wistar; Thromboxane B2; Weight Loss

Approaches to the treatment of lupus nephritis include immunosuppressants associated with anti-inflammatory drugs, mainly steroids, which, however, cause major side effects. Mycophenolate mofetil (MMF) has been described as being less toxic than conventional immunosuppressants, and it was effective in preventing progressive nephritis in lupus mice. Our study evaluated the therapeutic effect of MMF in NZB/W F1 hybrid mice with established disease. We also examined the combination of MMF with a selective cyclooxygenase-2 (COX-2) inhibitor, DFU, based on previous findings of excessive renal production of COX-2-derived thromboxane A2 (TXA2) in lupus nephritis.. Four groups of NZB/W mice (N = 30 each group), starting at five months of age, were given daily by gavage the following: vehicle, MMF 60 mg/kg, DFU 3 mg/kg, or MMF + DFU. Fifteen mice for each group were used for the survival studies, and the remaining mice were sacrificed at nine months.. MMF or DFU alone partially delayed the onset of proteinuria compared with vehicle. Combined therapy was significantly (P < 0.05) more effective than single drugs. Animal survival was partially ameliorated by MMF and significantly improved by the drug combination in comparison with the vehicle (P = 0.005) and DFU alone (P < 0.03). At nine months, serum blood urea nitrogen (BUN) levels were lower in all of the treated groups than in the vehicle group. Renal damage was also limited, but to a greater extent in mice given the combined therapy. In untreated mice, renal COX-2 mRNA expression was up-regulated, and generation of TXB(2), the stable breakdown product of TXA(2), increased. DFU prevented the abnormal renal TXB(2) production, confirming the COX-2 origin of this eicosanoid, whereas renal 6-keto-PGF(1 alpha) and prostaglandin E(2) (PGE(2)) were not affected substantially.. These results offer a strong case for exploring the possibility that in humans MMF combined with COX-2 inhibitors has a role in the treatment options for lupus nephritis. This combined drug therapy may be at least as effective as steroids but without the obvious nephrotoxicity of the latter.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antibodies, Antinuclear; Blood Urea Nitrogen; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Drug Therapy, Combination; Female; Furans; Gene Expression Regulation, Enzymologic; Immunosuppressive Agents; Isoenzymes; Kidney; Lupus Nephritis; Lymphocyte Count; Lymphocyte Subsets; Membrane Proteins; Mice; Mice, Inbred NZB; Mycophenolic Acid; Prostaglandin-Endoperoxide Synthases; Proteinuria; Spleen; Survival Rate; Thromboxane B2

No data are available about the effects of AT1 receptor antagonist losartan on the skeleton and there is also little information on the activity of an ACE inhibitor enalapril on bone metabolism. It is widely believed that the vasculature plays an important role in bone remodeling under normal and pathological conditions. We treated 14-week-old female Wistar rats with losartan, enalapril or saline. Administration of the ACE inhibitor enalapril and angiotensin II antagonist losartan had no effect on total malondialdehyde (MDA) in the blood and on urinary excretion of some eicosanoids and their metabolites. The administration of enalapril and losartan in a dose recommended for the treatment of hypertension did not cause significant changes in bone density, the ash and mineral content or morphometric parameters of the femur compared to the values found in control female rats.

Topics: 6-Ketoprostaglandin F1 alpha; Angiotensin Receptor Antagonists; Animals; Antihypertensive Agents; Bone Density; Dinoprost; Dinoprostone; Enalapril; F2-Isoprostanes; Female; Femur; Losartan; Proteinuria; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Thromboxane B2

1. Several lines of evidence indicate that thromboxane (Tx) A2 may contribute to the development and maintenance of hypertension. The present study was undertaken to evaluate the role of TxA2 in the development of hypertension in spontaneously hypertensive rats (SHR) by using an orally active, highly specific TxA2/prostaglandin H2 receptor antagonist S-1452. 2. Vehicle (1% arabic gum solution) alone was given orally to Wistar-Kyoto (WKY) rats (n = 15) and SHR (n = 14), while S-1452 (10 mg/kg per day, twice daily) was administered orally to SHR (n = 16) for 18 weeks (from 5 to 23 weeks of age). 3. No significant difference was observed in tail-cuff blood pressure (BP) between vehicle- and S-1452-treated SHR before and at 5 and 11 weeks after treatment. Thereafter, BP was further elevated in vehicle-treated SHR, but was significantly blunted in SHR treated with S-1452 at 15 (224+/-8 vs 211+/-13 mmHg; P < 0.01) and 18 weeks (227+/-9 vs 206+/-10 mmHg; P < 0.001); this was associated with reduced proteinuria. 4. Urinary TxB2 in vehicle-treated SHR, especially during the early period, was significantly greater than that in WKY rats, while no significant difference was observed in urinary 6-ketoprostaglandin F1alpha (6-keto-PGF1alpha) between the two groups. Treatment with S-1452 reduced urinary excretion of TxB2 at 18 weeks. 5. The present study shows that S-1452, at the dose used, does not reduce BP during the early period of the development of hypertension. These results suggest that the role of enhanced TxA2 production in the development of hypertension is small, if any, in SHR. Delayed response of BP may be independent of the direct pharmacological effects of S-1452.

Topics: 6-Ketoprostaglandin F1 alpha; Aldosterone; Animals; Antihypertensive Agents; Blood Pressure; Bridged Bicyclo Compounds; Dinoprostone; Fatty Acids, Monounsaturated; Hypertension; Male; Potassium; Prostaglandin Antagonists; Prostaglandins; Prostaglandins H; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptors, Prostaglandin; Receptors, Thromboxane; Renin; Sodium; Thromboxane B2; Time Factors

Cyclosporine (CsA) (45 mg/kg/day for 7 days) administration in female Wistar rats induced significant decrease in creatinine clearance (Ccr) and body weight loss (BWL). Urine volume (V) was not altered and proteinuria (PU) not provoked. These changes were associated with increased urinary endothelin 1 (ET-1) and thromboxane B(2)(TXB(2)) concentrations, and decreased urinary ratios of prostaglandin (6ketoPGF(1 alpha)and PGE(2)) to TXB(2)excretions. Nifedipine (NFD) (0.1 mg/kg/day for 7 days), a calcium channel blocker, administrated in addition to CsA, to another group of animals, significantly augmented Ccr and urine V but did not prevent BWL in comparison to CsA-only treated rats. The urinary ET-1 and TXB(2)concentrations displayed significant and non-significant decrease respectively, while the urinary excretion ratios of 6ketoPGF(1 alpha)/TXB(2)and PGE(2)/TXB(2)were significantly enhanced.These observations indicate that the partial protection of NFD in CsA-induced nephrotoxicity could be attributed to augmented urinary prostanoid ratios of renal vasodilators (6ketoPGF(1 alpha)and PGE(2)) to vasoconstrictor (TXB(2)) excretions, and also to reduced release of rather renal origin ET-1, the most potent mamalian vasoconstrictor peptide known to date. In a previous study, we found that NFD only slightly prevented structural renal damage, induced by CsA. So, the NFD protection refers only to functional toxicity and not to structural damage, mediated at least in part by the preservation of relatively high renal TXB(2)levels. However, other nephrotoxic factors and additional mechanisms could also be implicated in this CsA-induced syndrome.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Body Weight; Calcium Channel Blockers; Creatinine; Cyclosporine; Dinoprostone; Dose-Response Relationship, Drug; Endothelin-1; Endothelins; Enzyme Inhibitors; Female; Immunoassay; Kidney; Nifedipine; Proteinuria; Rats; Rats, Wistar; Spectrophotometry; Thromboxane B2; Urine

To clucidate the mechanism of the therapeutic effect of Yiqi Huoxue (YQHX) serial recipes on membranous nephritis.. Forty-nine New Zealand male rabbits were made to menbranous nephritis model by cation bovine serum albumin and divided into 5 groups, the group A (treated by Qingre Moshen granule), B (treated by Bushen Moshen granule), C (treated by steroid), D (the control group) and E (the normal group). Twenty-four hours' urinary protein content of the animals was determined every week, and plasma albumin, blood lipid, renal function and prostaglandins were tested by the end of experiment. And pathological changes of basement membrane were observed by using light, electronic and immunofluorescent microscopy with polyethylene imine stain.. The 24 hours urinary protein content, plasma albumin and blood lipid in the group A and B were lower than those in the control group significantly, P < 0.01 or 0.05, while those in the group C and the D were similar, P > 0.05. In comparing the group A and B with the group C, the difference was also significant, P < 0.05. Light, electronic and immunofluorescent microscopic examination all showed that the pathologic changes in the group A, B and C were lesser than that of the control, the effect was in the order A > B > C.. YQHX serial recipes can reduce urinary protein content, elevate plasma albumin level, restore the charge barrier effect of and attenuate the immune complex deposition on the basement membrane of glomeruli.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Basement Membrane; Drugs, Chinese Herbal; Glomerulonephritis, Membranous; Male; Proteinuria; Rabbits; Random Allocation; Serum Albumin; Thromboxane B2

The antinephritic effect of lipo-prostaglandin E1, prostaglandin E1 ((1R,2R,3R)-3-hydroxy-2-[(E)-(3S)-3-hydroxy-1-octenyl]-5-oxocyclopent ane heptanoic acid) incorporated in lipid microspheres was investigated using an experimental model of nephritis, crescentic-type anti-glomerular basement membrane nephritis. Lipo-prostaglandin E1 was given i.v. twice a day at 20, 40 and 80 microg/kg and azathioprine, an immunosuppressive agent, at 20 mg/kg was given p.o. once daily from the autologous phase, in which glomerulonephritis was fully developed (the 21 st day after injection of the anti-glomerular basement membrane serum), to the 50th day. Lipo-prostaglandin E1 (40 and 80 microg/kg x 2 per day) significantly inhibited the development of glomerular alterations as well as the elevation of proteinuria and plasma creatinine. Lipo-prostaglandin E1 (20 microg/kg x 2 per day) and azathioprine (20 mg/kg per day) significantly inhibited only the glomerular histopathological changes. Lipo-prostaglandin E1 at three doses significantly decreased the deposition of both rabbit immunoglobulin G and rat immunoglobulin G on the glomerular basement membrane in nephritic rats, but azathioprine apparently inhibited only the deposition of rat immunoglobulin G. A single administration of lipo-prostaglandin E1 inhibited the elevation of platelet aggregation and restored the decrease in renal tissue blood flow in nephritic rats. In addition, a single administration of lipo-prostaglandin E1 inhibited the elevation of glomerular thromboxane B2 and 6-keto prostaglandin F1alpha production in nephritic rats. These results suggest that lipo-prostaglandin E1 may be an effective agent for the treatment of glomerulonephritis. Its antinephritic effect may be due to the inhibition of platelet aggregation, an increase in renal tissue blood flow, a decrease in rabbit and rat immunoglobulin G deposition, and amelioration of the abnormal metabolism of arachidonic acid.

Topics: 6-Ketoprostaglandin F1 alpha; Alprostadil; Animals; Basement Membrane; Creatinine; Glomerulonephritis, Membranous; Immunoenzyme Techniques; Kidney; Liposomes; Male; Proteinuria; Rats; Rats, Sprague-Dawley; Thromboxane B2

The cause of proteinuria in passive Heymann nephritis has been attributed to the activation of the C5b-9 membrane attack complex following the antibody binding on the glomerular epithelial cell. Previous studies have shown an association between release of prostaglandin thromboxane B2 (TxB2) and proteinuria. Whether this release is dependent on antibody binding per se, or on secondary actions subsequent to antibody binding has not been clarified. The present study was designed to address this issue. Antibody binding event was experimentally separated from the proteinuria by employing a rabbit antibody which produces equivalent glomerular binding equal to that produced by a sheep antibody but without causing proteinuria. Comparisons were made with animals injected with the sheep antibody which produces all the hallmarks of the disease, including proteinuria. Animals injected with the rabbit antibody showed glomerular immunofluorescent deposits which were identical to the deposits produced by the control sheep antibody. However, rabbit antibody failed to produce the typical electron-dense subepithelial deposits, complement binding and proteinuria. Comparison of prostaglandin profile in isolated glomeruli revealed that TxB2 was unchanged in rabbit antibody-injected glomeruli (compared with its nonimmune antibody control). On the other hand, glomeruli from sheep antibody-injected animals released 45% higher TxB2 compared with their respective nonimmune antibody control. These data suggest that the binding of antibody per se may not be a sufficient stimulus for TxB2 release. Subsequent events of subepithelial electron dense deposit formation, complement activation, and proteinuria are associated with TxB2 release.

Topics: Animals; Complement Membrane Attack Complex; Disease Models, Animal; Eicosanoids; Fluorescent Antibody Technique, Direct; Glomerulonephritis; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Sprague-Dawley; Thromboxane B2

Mizoribine (MZR), a purine nucleoside antibiotic, is an effective immunosuppressive agent that prevents rejection reactions after kidney transplantation in humans. The present study was performed to examine the effect of MZR on nephrosis produced in rats given puromycin aminonucleoside (PAN). Urinary protein excretion in rats injected with PAN and MZR (PAN + MZR rats) was shown to be reduced significantly in comparison with rats given only PAN (PAN rats). Although mild hypoproteinemia persisted during the experimental period in PAN + MZR rats, no loss of body weight or state of malnutrition was observed. The reduction of serum IgG and C3 was reversed by administration of MZR. Polyethyleinamine (PEI) staining of renal sections showed increased numbers of anionic sites in PAN + MZR rats in comparison with PAN rats, suggesting that MZR improved the permselectivity of the glomerular basement membrane (GBM). Moreover, the production of thromboxane B2 (TxB2) was significantly inhibited in PAN + MZR rats compared with PAN rats. No serious adverse effects of MZR were observed after a large dose of the agent. It is possible that restoration of the charge barrier of the GBM damaged by PAN, or reduction of TxB2 production by the glomeruli may underlie the reduction of protein excretion induced by administration of MZR.

Topics: Animals; Antibiotics, Antineoplastic; Immunosuppressive Agents; Male; Nephrosis; Nephrosis, Lipoid; Proteinuria; Puromycin Aminonucleoside; Rats; Rats, Wistar; Ribonucleosides; Thromboxane B2

The antinephritic effect of DP-1904 [6-(1-imidazolylmethyl)-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid hydrochloride], a thromboxane A2 synthase inhibitor, was evaluated using an experimental model of membranous nephropathy, viz. accelerated passive Heymann nephritis in which the glomerular injury is mediated by immune complexes. DP-1904 markedly inhibited the develop-ent of glomerular alteration as well as the elevation of proteinuria and plasma creatinine. When the treatment was started from the 22nd day, at which time proteinuria is fully developed, DP-1904 showed beneficial effects on proteinuria and glomerular histopathological changes. DP-1904 apparently decreased the deposition of both rabbit immunoglobulin G and rat immunoglobulin G on glomerular basement membrane in nephritic rats. A single administration of DP-1904 restored the decreased renal tissue blood flow, inhibited glomerular thromboxane B2 production and increased glomerular prostaglandin E2 and 6-keto prostaglandin F1 alpha production in nephritic rats. These results suggest that DP-1904 may be an effective agent for the treatment of idiopathic membranous nephropathy and that the beneficial effect of this drug may be due to the elimination of glomerular immune deposits and to an increase in renal tissue blood flow related to amelioration of the abnormal metabolism of arachidonic acid.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antibodies; Azathioprine; Creatinine; Dinoprostone; Drug Interactions; Enzyme Inhibitors; Glomerulonephritis; Imidazoles; Immunoglobulin G; Immunosuppressive Agents; Kidney Glomerulus; Male; Methacrylates; Proteinuria; Rabbits; Rats; Rats, Sprague-Dawley; Renal Circulation; Tetrahydronaphthalenes; Thromboxane B2; Thromboxane-A Synthase

The objective of this study was to assess the effects of flaxseed and flax oil diets in the rat renal ablation model. Flaxseed is a rich source of alpha-linolenic acid, an 18:3n3 omega-3 fatty acid, which has anti-atherogenic and anti-inflammatory properties. Flaxseed, but not flax oil, is also rich in lignans, which are platelet-activating factor-receptor antagonists. Rats were subjected to 5/6 nephrectomy, fed a regular laboratory diet (RLD) for 1 week, then divided into three groups to receive either the RLD (n = 8), a 15% flaxseed diet (n = 8), or a 15% flax oil diet (n = 7). Blood pressure, proteinuria, glomerular filtration rate, and urinary prostaglandins (thromboxane B2 and 6-keto prostaglandin F1 alpha) were measured presurgery and at 1 week (before dietary allotment) and 20 weeks postnephrectomy when blood for plasma lipids and kidneys for histology and tissue-phospholipid analyses were obtained. Blood pressure increased progressively in the RLD group but not in the flax diet groups. Plasma triglycerides and cholesterol increased in all groups, but this increase was significantly attenuated by both flax diets. Proteinuria increased 1 week postsurgery and continued to increase in the RLD group but not in the flax diet groups. Glomerular filtration rate decreased progressively, but this decline in renal function was attenuated significantly by the flax diets. Both of the flax diets prevented glomerulosclerosis and mesangial expansion. Renal alpha-linolenic acid was increased by both the flax diets (flax oil > flaxseed), but eicosapentaenoic acid increased in the flax oil group only. The flaxseed group had greater renal-arachidonic acid levels than the flax oil and RLD groups. The total omega-3 fatty acids increased twofold to threefold in the flax oil group compared with the two other groups. The total saturated fatty acids were lower and the polyunsaturated fatty acids were increased in both flax diet groups. A progressive increase in urinary thromboxane B2 occurred in the RLD group but not in the flaxseed group; the level decreased in the flax oil group. The ratio of prostaglandin F1 alpha/thromboxane B2 was preserved in the flax oil group only. In conclusion, the dietary flax seed and flax oil attenuated the decline in renal function and reduced glomerular injury with favorable effects on blood pressure, plasma lipids, and urinary prostaglandins. While we have not proven any specific synergistic effects of the constituents of the flaxseed diet,

Topics: 6-Ketoprostaglandin F1 alpha; alpha-Linolenic Acid; Analysis of Variance; Animals; Blood Pressure; Disease Models, Animal; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Kidney; Kidney Failure, Chronic; Ligation; Linseed Oil; Lipids; Male; Nephrectomy; Plants, Edible; Proteinuria; Rats; Rats, Sprague-Dawley; Renal Artery; Seeds; Thromboxane B2

In rats with incipient adriamycin nephropathy, pregnancy increases urine protein excretion and mean arterial pressure, with no changes in the glomerular filtration rate. Renal histology is normal and the glomerular TxB2/PGE2 ratio is increased.. In the present study we evaluated the influence of repeated pregnancies on the evolution of adriamycin nephropathy. Two weeks after a first delivery, rats were mated again and were followed till 35 days after the second delivery.. In pregnant rats with adriamycin nephropathy, urine protein excretion and mean arterial pressure returned to values identical to those found in age-sex-matched virgin rats with adriamycin nephropathy. At the end of the second pregnancy, mean arterial pressure and urine protein excretion were again elevated, compared with virgin rats with adriamycin nephropathy. Thirty-five days after the second delivery, urine protein excretion and mean arterial pressure remained elevated, 296 +/- 50 mg/day vs 115 +/- 26 and 121 +/- 4 vs 110 +/- 1 mmHg respectively, P < 0.05. Glomerular filtration rate remained unchanged 0.84 +/- 0.09 vs 0.79 +/- 0.09 ml/min in virgin rats with adriamycin nephropathy. The glomerular TxB2/PGE2 ratio was decreased, contrasting with the first pregnancy. At the end of the second pregnancy, histological examination of the kidneys in rats with adriamycin nephropathy revealed a significant increase in mesangial expansion. It was even more marked 35 days later, at the last follow-up, with a semiquantitative score of 162 +/- 29 vs 81 +/- 20 in virgin adriamycin nephropathy rats, P < 0.05.. In rats with adriamycin nephropathy, repetitive pregnancies seem to aggravate the natural course of the disease in an irreversible fashion. The earlier changes in glomerular prostanoid synthesis, particularly on thromboxane, may play a pathogenic role by activating mesangial cell matrix synthesis.

Topics: Animals; Blood Pressure; Dinoprostone; Doxorubicin; Female; Glomerular Filtration Rate; Kidney Diseases; Kidney Glomerulus; Pregnancy; Pregnancy Complications; Proteinuria; Rats; Rats, Wistar; Recurrence; Thromboxane B2

A number of chemicals may adversely affect one or more of the anatomical structures of the kidney, such as the glomerulus, the tubular apparatus, the medullary, or interstitial cells. To recognize subclinical renal dysfunction, a battery of new, non-invasive tests was applied in comparison to established ones. The study on cadmium exposed subjects, performed within the framework of a collaborative European research project, exemplifies the concept of target selectivity within a nephron. One hundred seventy-two subjects were classified according to urinary cadmium excretion as controls (< 1.5 micrograms/g creatinine), or subjects with moderate or high cadmium body burden (1.5 to 5 micrograms/g creatinine, > 5 micrograms/g creatinine). Twenty-six urinary analytes (such as serum derived proteins, tubular enzymes, eicosanoids) and four plasma markers, related to the function or integrity of specific nephron segments, were investigated in a cross-sectional study. The group with the moderate cadmium body burden showed alterations of proximal tubular integrity, that is, increased excretion of tubular brush-border antigens. The group with higher cadmium body burden revealed an involvement of the whole nephron. The most prominent quantitative changes were found for the glomerular markers high molecular weight proteins, and thromboxane B2 and for the proximal tubular markers retinol binding protein, alpha 1-microglobulin, N-acetyl-beta-D-glucosaminidase, and the intestinal alkaline phosphatase. A diagnostic approach to screen for nephrotoxicity due to environmental hazards like cadmium should include proximal tubular markers (alpha 1-microglobulin and tubular enzymes, that is, intestinal alkaline phosphatase) but the measurement of glomerular markers is also advisable.

Topics: Adult; Biomarkers; Body Burden; Cadmium; Discriminant Analysis; Female; Humans; Kidney Glomerulus; Kidney Tubules, Distal; Kidney Tubules, Proximal; Loop of Henle; Male; Middle Aged; Molecular Weight; Nephrons; Occupational Exposure; Proteins; Proteinuria; Thromboxane B2

The antinephritic effect of DP-1904 [6-(1-imidazolylmethyl)-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid hydrochloride], a thromboxane A2 synthetase inhibitor, was compared with that of OKY-046, using an experimental model of nephritis, crescentic-type anti-glomerular basement membrane nephritis. Test drugs were given p.o. once daily from the day after the the development of glomerular alteration as well as the elevation of proteinuria and plasma cholesterol. On the other hand, OKY-046 (20 mg/kg per day), a thromboxane A2 synthetase inhibitor, significantly inhibited only deterioration in the glomeruli. DP-1904 and OKY-046 inhibited glomerular thromboxane B2 production and increased glomerular prostaglandin E2 and 6-keto prostaglandin F1 alpha production in normal and nephritic rats. Both drugs inhibited the increase in platelet aggregability, restored decreased renal tissue blood flow to a near-normal level and decreased the deposition of rat immunoglobulin G on glomerular basement membrane in nephritic rats. These results suggest that DP-1904 may be an effective agent for the treatment of proliferative glomerulonephritis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Basement Membrane; Cholesterol; Dinoprostone; Fluorescent Antibody Technique; Imidazoles; Kidney Glomerulus; Male; Methacrylates; Nephritis, Interstitial; Platelet Aggregation; Proteinuria; Rats; Rats, Sprague-Dawley; Tetrahydronaphthalenes; Thromboxane B2; Thromboxane-A Synthase

Passive Heymann nephritis (PHN) is a rat model of membranous nephropathy induced by injecting anti-Fx1A. The onset of proteinuria in PHN is caused by complement-mediated injury to glomerular epithelial cells (GEC) accompanied by enhanced glomerular eicosanoid production. In addition, sublethal injury by complement of rat GECs in culture leads to phospholipase activation, phospholipid hydrolysis and release of arachidonic acid and dienoic prostanoids. Based on these findings, we undertook to determine if substituting arachidonic acid (omega-6) in GEC membrane phospholipids with omega-3 fatty acids derived from fish oil would alter the development and course of proteinuria in PHN. We found that rats fed a diet containing 10% fish oil for four weeks prior to antibody injection developed 50 to 60% less proteinuria between two and six weeks after anti-Fx1A than rats fed an equivalent diet containing 10% safflower oil, and had substantial enrichment of glomerular phospholipids with omega-3 fatty acids and displacement of arachidonic acid. This outcome was associated with a 50% reduction in release of glomerular thromboxane B2 (stable metabolite of thromboxane A2) in the fish oil group. More importantly, when PHN rats with well established proteinuria while on regular chow were randomized to three dietary groups, those fed fish oil had a 25 to 50% decline in proteinuria as compared to those fed lard or safflower oil. This difference was evident within two weeks of randomization and persisted until the end of the study after eight weeks. In neither study could the differences in urine protein excretion be accounted for by protein or calorie deprivation, or by differences in blood pressure, renal function, immune response to sheep IgG, or glomerular deposition of IgG or complement. Thus, our results indicate that dietary fish oil has protective and therapeutic effects with regard to proteinuria in PHN. These benefits may relate to alterations in membrane phospholipid composition in favor of omega-3 fatty acids and release of less reactive trienoic eicosanoids.

Topics: Animals; Fatty Acids; Fatty Acids, Omega-3; Female; Fish Oils; Glomerulonephritis; Kidney Glomerulus; Lipids; Phospholipids; Proteinuria; Rats; Rats, Sprague-Dawley; Renal Circulation; Thromboxane B2

Spontaneously hypertensive rats (SHR) were injected with streptozotocin (STZ-SHR) to induce diabetes. The effect of DP-1904, a thromboxane A2 synthetase inhibitor, on diabetic nephropathy was then studied by administering it for 5 months (1 or 10 mg/kg). DP-1904 did not affect renal 6-keto prostaglandin (PG)F1 alpha production in STZ-SHR, but markedly inhibited renal thromboxane (TX) B2 production, so that the 6-keto PGF1 alpha/TXB2 ratio was significantly increased (P less than 0.05). STZ-SHR showed significant uraemia and proteinuria, plus increases in urinary gamma-glutamyl-transpeptidase and urinary N-acetyl-beta-glucosaminidase. DP-1904 significantly decreased (P less than 0.01) the urinary changes. STZ-SHR also showed an increase in mesangial periodic acid-Schiff-positive substance and in relative renal weight, both of which were significantly inhibited by DP-1904 (P less than 0.05). Thus, DP-1904 inhibited both TXB2 production and the progression of renal damage in STZ-SHR.

Topics: Acetylglucosaminidase; Animals; Blood Pressure; Diabetes Mellitus, Experimental; Diabetic Nephropathies; gamma-Glutamyltransferase; Heart Rate; Hypertension; Imidazoles; Kidney; Prostaglandins; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Tetrahydronaphthalenes; Thromboxane B2; Thromboxane-A Synthase

Twelve Beagles were inoculated with concanavalin A, and after a mean ninefold increase in antibody titer, 1 mg of concanavalin A was infused into each renal artery of each dog to induce in situ immune complex glomerulonephritis. Starting 4 weeks after renal arterial infusion, 6 dogs were treated orally 3 times daily with 30 mg of 3-methyl-2 (3 pyridyl)-1-indolectanoic acid (CGS 12970)/kg of body weight, a thromboxane synthetase inhibitor, and 6 dogs (control group) received a gelatin capsule 3 times daily. Endogenous creatinine clearance and 24-hour urinary excretion of protein and thromboxane B2 were determined for each dog prior to renal arterial infusion, at the initiation of treatment and at 2, 4, 6, and 8 weeks after initiation of treatment. In addition, methyoxy-3H inulin clearance was determined at initiation of treatment and 4 and 8 weeks later. Renal specimens were examined histologically at the initiation of treatment and 4 and 8 weeks later. Glomerular mononuclear profiles/microns 3 were determined from at least 10 equatorially sectioned glomeruli from each dog. Paired t tests were used to compare mean values at the various time points to the respective mean baseline value and 2-sample t tests were used to evaluate differences between treatment groups. At the start of treatment (4 weeks after renal arterial infusion of concanavalin A), histologic evaluation of renal specimens revealed glomerular epithelial crescent formation, mononuclear cell proliferation, and infiltration of neutrophils. Mononuclear cell profiles and urinary excretion of protein and thromboxane B2 were significantly increased, but endogenous creatinine clearance values were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antibodies; Concanavalin A; Creatinine; Dog Diseases; Dogs; Glomerular Filtration Rate; Glomerulonephritis; Immune Complex Diseases; Kidney; Male; Proteinuria; Pyridines; Thromboxane B2; Thromboxane-A Synthase

The effect of orally administered Oenothera Biennis L on chronic renal failure was studied in the partially nephrectomized rats. As compared with the control groups, the group treated with Oenothera showed the following features. 1) Urine protein excretion was reduced; 2) Level of serum cholesterol decreased; 3) Scr maintained the same level as before treatment; 4) Level of PGE1 and PGE2 increased both in renal cortex and medulla; 5) 6-keto PGF1 alpha increased in cortex; 6) Increased TXB2 production was only observed 4 weeks after nephrectomy; 7) Glomerular lesions were more severe in control group. It is concluded that Oenothera Biennis L has beneficial effect on the remnant kidney and may be useful as a kind of conservative treatment for chronic renal failure.

Topics: 6-Ketoprostaglandin F1 alpha; Alprostadil; Animals; Dinoprostone; Drugs, Chinese Herbal; Kidney; Kidney Failure, Chronic; Male; Nephrectomy; Proteinuria; Rats; Rats, Wistar; Thromboxane B2

The present study was conducted to investigate the antinephritic effects of berberine and coptisine, which are contained in Coptidis rhizoma, on original-type anti-GBM nephritis in rats. Berberine and coptisine at the doses of 0.5, 1.0 and 5.0 mg/kg/day, i.p. were effective in inhibiting urinary protein excretion, elevation of serum cholesterol and creatinine contents as well as glomerular histopathological changes. In addition, berberine at 20 mg/kg/day, p.o. also inhibited urinary protein excretion throughout the experimental periods. Berberine and coptisine inhibited platelet aggregation in both in vitro and in vivo assays, and berberine inhibited the decline of renal blood flow. Although berberine inhibited an increase in thromboxane B2 formation, it increased the formation of 6-keto-prostaglandin F1 alpha in platelets and isolated glomeruli. These results indicate that the antinephritic effects of berberine and coptisine may be partly due to antiplatelet action and improved renal hemodynamics via changing prostanoid synthesis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Berberine; Cholesterol; Creatinine; Dipyridamole; Drug Evaluation, Preclinical; In Vitro Techniques; Male; Nephritis; Plant Extracts; Platelet Aggregation; Proteinuria; Rats; Rats, Sprague-Dawley; Renal Circulation; Thromboxane B2

Vasoactive eicosanoids may be involved in glomerular hyperfiltration following a high protein intake or removal of renal mass. We sequentially measured glomerular filtration rate (GFR), proteinuria (UpV), and urinary eicosanoid excretion in sham-operated (2K) and uninephrectomized (NX) rats on two diets. Compared with 12% protein (LP), 36% protein (HP) initially resulted in a higher GFR and UpV in both 2K and NX rats. Urinary excretion of 6kPGF1 alpha and TxB2 was higher on the HP diet. Ten weeks after NX, PGE2 excretion was slightly reduced, while that of TxB2 and 6kPgF1 alpha was the same as in 2K rats, indicating that the excretion per kidney had increased. From week 40, the GFR of NX rats on the HP decreased, preceded by a progressive increase in UpV. Excretion of PgE2, TxB2, and 6kPgF1 alpha was highest in the phase of proteinuric chronic renal failure. Thus, vasoactive eicosanoids are involved to maintain hyperfiltration induced by high protein intake or NX.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Dietary Proteins; Eicosanoids; Glomerular Filtration Rate; Kidney; Male; Nephrectomy; Proteinuria; Random Allocation; Rats; Rats, Wistar; Thromboxane B2

The administration of a single-injection of Adriamycin (ADR) to rats results in marked proteinuria and glomerular morphological changes that are similar to minimal change disease in humans. We have hypothesized that Adriamycin, by itself or through the release of some mediators from resident glomerular cells, could provoke a damage to epithelial glomerular cells. Sprague-Dawley rats received a single injection of Adriamycin, 7.5 mg/kg bw, allocated randomly in several groups and treated throughout 2 weeks of follow-up. All control nontreated animals developed important nephrotic syndrome and degenerative lesions of epithelial glomerular cells. Isolated glomeruli from animals injected with adriamycin 14 days before synthesized thromboxane (TxB2) and platelet activating factor (PAF) in amounts above the rates of control glomeruli. Animals treated with three structurally different PAF receptor antagonists did not present proteinuria or only to a very low extent (p less than 0.0005). In these rats no alterations in epithelial cells were noted. Furthermore, no significant changes in the TxB2 production were noted in rats treated with BN 52021, a PAF receptor antagonist. Leukotrienes also seem to participate since treatment with a 5-lipoxygenase inhibitor partially corrected proteinuria. Moreover, glomeruli from animals with nephrosis and treated with this compound presented only a discrete reduction in the PAF synthesis. On the whole, these data suggest a key role for PAF in the pathogenesis of adriamycin nephropathy. Other lipid meditors, released in cascade simultaneously or thereafter, could perpetuate the renal damage.

Topics: Animals; Dinoprostone; Doxorubicin; Kidney Glomerulus; Lipoxygenase Inhibitors; Male; Nephrosis, Lipoid; Platelet Activating Factor; Platelet Membrane Glycoproteins; Proteinuria; Random Allocation; Rats; Rats, Inbred Strains; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Thromboxane B2

Topics: Anti-Inflammatory Agents, Non-Steroidal; Dinoprostone; Glomerular Filtration Rate; Humans; Proteinuria; Sulindac; Thromboxane A2; Thromboxane B2

Haemostatic activation was measured in patients with either non-diabetic chronic renal failure (CRF) or diabetic nephropathy. We have investigated the relationship between these haemostatic markers and the rate of progression of renal failure. When compared with age- and sex-matched healthy controls, both patient groups showed significantly elevated plasma concentrations of D dimer, von Willebrand factor antigen (vWFAg), and C-reactive protein (CRP) (all P less than 0.001), as well as an increase in spontaneous platelet aggregation (P less than 0.01). Plasma concentration of platelet factor 4 was slightly but not significantly increased. Serum thromboxane was subnormal (P less than 0.01). Multiple regression analysis showed that in non-diabetic CRF proteinuria and serum TxB2 were independently related to the rate of progression of renal failure; in diabetic nephropathy proteinuria and vWFAg were independently related to the rate of progression. In both groups the relationship was stronger with proteinuria (standardised regression coefficients 0.56 and 0.45 respectively) than with serum TxB2 (0.29) or with vWFAg (0.37). We have found haemostatic activation in both non-diabetic and diabetic progressive renal failure. Proteinuria, and also in this study serum TxB2 and vWFAg, appear to be determining factors in the progression of renal failure, and their measurement may have prognostic value.

Topics: Adolescent; Adult; Aged; Antigens; Diabetic Nephropathies; Female; Glomerulosclerosis, Focal Segmental; Hemostasis; Humans; Kidney; Kidney Failure, Chronic; Male; Middle Aged; Platelet Activation; Proteinuria; Thromboxane B2; von Willebrand Factor

An evaluation was made of the possible relation between renal thromboxane (Tx)A2 synthesis (measured as urinary excretion of TxB2) and the loss of glomerular permeability to proteins, in 5 children with seven episodes of minimal change nephrotic syndrome. Urinary TxB2 excretion was significantly higher in children with minimal change nephrotic syndrome than in 14 healthy controls, and reached its maximum at the time of peak proteinuria. During remission of nephrotic syndrome urinary excretion of TxB2 was still significantly higher than in healthy controls. A significant positive correlation between urinary excretion of TxB2 and proteinuria was observed in 3 patients. The results suggest that renal TxA2 could be regarded as one of the possible mediators of the altered glomerular permeability to proteins in minimal change nephrotic syndrome.

Topics: Child; Female; Humans; Kidney; Male; Nephrosis, Lipoid; Proteinuria; Thromboxane A2; Thromboxane B2

To examine the effects of endogenous thromboxane A2 on the development of diabetic nephropathy, we administered OKY-046, an inhibitor of thromboxane synthesis, to streptozotocin-induced diabetic rats. Animals were divided into three groups; nondiabetic control, diabetic, and diabetic with OKY-046, and were sacrificed 16 weeks after experimental procedures. The chronic oral administration of OKY-046 to diabetic rats significantly decreased plasma and urinary thromboxane B2 levels. Urinary protein excretion and serum glucose levels were significantly lower in the OKY-046-treated diabetic rats than in the untreated diabetics (60.8 +/- 23.2 vs. 94.1 +/- 33.4 mg/day in the 16th week, p less than 0.05 and 424.4 +/- 93.3 vs. 614.4 +/- 102.3 mg/dl in the 16th week, p less than 0.01, respectively). Platelet aggregation was inhibited by OKY-046. Blood urea nitrogen was unaffected. Ultrastructural examination revealed that the thickness of glomerular basement membrane was markedly thinner in the OKY-046-treated diabetic rats than in the untreated diabetics (197.4 +/- 29.6 vs. 288.6 +/- 46.9 nm, p less than 0.01). These results suggest that thromboxane A2 may play an important role in the development and progression of diabetic nephropathy in rats.

Topics: 6-Ketoprostaglandin F1 alpha; Administration, Oral; Animals; Blood Glucose; Blood Pressure; Blood Urea Nitrogen; Body Weight; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Insulin; Kidney; Male; Methacrylates; Microscopy, Electron; Platelet Aggregation; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane A2; Thromboxane B2; Thromboxane-A Synthase

Previous studies have demonstrated that inhibition of thromboxane A2-dependent platelet aggregation by the thromboxane A2 synthase inhibitor, OKY 1581, ameliorated the progressive kidney disease of rats with subtotal renal ablation. OKY 1581 also decreased the excessive renal thromboxane A2 synthesis and lowered systemic blood pressure. In the same model, a low dose aspirin and a specific thromboxane A2 receptor antagonist failed to influence proteinuria, glomerulosclerosis, and hypertension, thus excluding a role for either platelet or renal thromboxane A2 in renal disease progression. The aims of this study were to establish (1) whether a thromboxane A2 synthase inhibitor different from OKY 1581 could retard the progression of glomerular disease in rats with remnant kidney and (2) whether this effect was associated with an increase in renal synthesis of the vasodilatory prostacyclin. Treatment of rats with renal mass ablation with FCE 22178 (100 mg/kg by gavage and 200 mg/kg in the drinking water) for 35 days starting 10 days after surgical ablation was associated with an improvement in renal function in comparison with rats receiving the vehicle alone. Proteinuria was significantly lower, and rats were partially protected from the development of glomerulosclerosis. Systolic blood pressure was significantly lower than in animals given the vehicle. Urinary thromboxane B2 excretion was significantly decreased, and urinary 6-keto-prostaglandin F1 alpha increased in respect to vehicle-treated rats. We conclude that FCE 22178 limits glomerular injury in rats with remnant kidney.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bleeding Time; Blood Pressure; Epoprostenol; Imidazoles; Kidney; Kidney Diseases; Male; Naphthalenes; Platelet Aggregation; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane B2; Thromboxane-A Synthase; Thromboxanes

Dietary fish oil intake improves glomerular pathology and proteinuria in murine models of autoimmune disease. We evaluated glomerular prostanoid formation, glomerular hemodynamics, and proteinuria in rats with nephrotoxic serum nephritis (NSN) to test whether this beneficial effect of marine lipids also applies to other animal models of glomerular immune injury. Rats were fed diets (8 weeks) containing either cod liver oil or sunflower oil. NSN was induced with a rabbit anti-rat glomerular basement membrane antiserum. Antibody injection significantly stimulated glomerular thromboxane B2 (TxB2) formation in animals fed cod liver oil and sunflower oil at 2 hours, 24 hours, and 7 days. TxB2 production in glomeruli of sunflower oil rats, however, was five to seven times higher when compared with that in rats fed cod liver oil. The dietary regimen led to a significant decrease of glomerular TxB2 and prostaglandin E2 formation in the animals receiving cod liver oil when compared with those fed sunflower oil. Induction of NSN resulted in a significant fall of inulin clearance (Cin) and paraaminohippurate clearance at 2 hours, 24 hours, and 7 days in both groups. The decrease in Cin at 2 hours was greater in rats fed cod liver oil when compared with animals receiving sunflower oil (p less than 0.02); it was not different, however, at 24 hours and 7 days. Animals with NSN developed proteinuria. There was no difference in protein excretion between rats fed cod liver oil or those fed sunflower oil (days 2 and 7).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Diet; Dinoprostone; Eicosanoids; Fish Oils; Glomerular Filtration Rate; Hemodynamics; Immune Sera; Insulin; Kidney Glomerulus; Leukotrienes; Metabolic Clearance Rate; Nephritis; p-Aminohippuric Acid; Proteinuria; Rabbits; Rats; Thromboxane B2

Thromboxane contributes to the regulation of glomerular hemodynamics in experimental models of diabetes and has been implicated as mediator in some models of glomerular injury. In the present study we examined urinary albumin, protein, and thromboxane B2 (TXB2) excretion during the 170 days after induction of diabetes by injection of streptozotocin in insulin-treated moderately hyperglycemic (200 to 400 mg/dl glucose) rats (SDRs). The effects of a thromboxane synthesis inhibitor, 4'-(imidazol-1-yl)acetophenone (TXI) (100 mg/kg/day) on these parameters were also assessed. Urinary TXB2 and albumin excretion in SDRs was not different from that in normal rats between 7 and 90 days but were three times higher than normal in SDRs at 125 and 170 days after induction of diabetes. In SDRs, urinary protein excretion was higher than in controls at 170 days but not at earlier time points. Inulin clearance (CIn) of SDRs was significantly higher than control values at 7 and 90 days and was not influenced by TXI during this period. At 170 days CIn was not significantly different in SDRs and normal rats. By contrast, albumin clearance (CAIb) and fractional CAIb were elevated in SDRs when compared with those values in normal rats. Treatment of SDRs with TXI for 170 days completely prevented the rise in urinary TXB2, albumin, and protein excretion, as well as the rise in fractional CAIb, but did not alter prostaglandin E2 (PGE2) excretion. TXI also increased CIn in SDRs to levels that were significantly higher than normal at 170 days. TXI had no significant effect on urinary PGE2, TXB2, albumin, or protein excretion or on CIn in normal rats and did not influence blood pressure or blood glucose in normal rats or SDRs. The results suggest a role for thromboxane in the mediation of albuminuria in the SDR.

Topics: Albuminuria; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Dinoprostone; Female; Glomerular Filtration Rate; Imidazoles; Proteinuria; Rats; Rats, Inbred Strains; Reference Values; Serum Albumin; Thromboxane B2; Thromboxanes

The efficacy of dietary intervention with either 6% protein restriction, fish oil or safflower oil was assessed in the remnant nephron model. Female Munich Wistar rats were prefed for one week prior to 5/6 nephrectomy and followed for the ensuing 28 days. Fish oil, safflower oil and protein restriction prevented the gammaglobulinuria but only fish oil lessened the albuminuria in this model. The remnant nephrons of the fish oil treated rats contained less arachidonic acid and greater quantities of eicosapentaenoic and docosahexaenoic acid than the safflower oil or lab chow fed control rats. The fish oil, and to a lesser extent the safflower oil, treated animals had a higher ratio of 6 keto PGF1 alpha to TX B2 metabolites in their urine. We suggest these changes may be responsible for the lessening in urine protein excretion. Fish oil feeding was more effective than severe protein restriction or safflower oil dietary supplementation in lessening both the gammaglobulinuria and albuminuria of the remnant nephron model.

Topics: 6-Ketoprostaglandin F1 alpha; Albuminuria; Animals; Arachidonic Acids; Dietary Fats; Dietary Proteins; Fatty Acids, Unsaturated; Female; Fish Oils; Immunoglobulin G; Nephrectomy; Nephrons; Proteinuria; Rats; Safflower Oil; Thromboxane B2

Fish oil diets preserve renal function in murine lupus, but we have found that these diets accelerate renal deterioration in renoprival nephropathy. In this study we examined the effects of dietary fish oil in accelerated nephrotoxic serum nephritis. For 1 month, 14 female rats were fed diets that differed only in fat composition, containing either menhaden (fish) oil or beef tallow (control). Rats were then preimmunized with rabbit IgG and, 5 days later, were injected with nephrotoxic serum. Glomerular filtration rate (GFR) was measured continuously in conscious animals by means of intraperitoneal 14C-labeled inulin minipumps. Fish oil-containing diets markedly attenuated the nephrotoxic serum-induced decline in GFR and the rise in proteinuria and significantly reduced glomerular prostaglandin E2 and thromboxane A2. The results of tests of renal histology showed no differences between the two groups. Five days after preimmunization, rats fed fish oil had more rabbit IgG remaining in their serum and had mounted less of an antibody response to the rabbit IgG. Fish oil diets also resulted in an attenuated disappearance of injected 14C-labeled rabbit IgG. In vitro, peritoneal macrophages from rats fed fish oil took up less rabbit IgG than macrophages from rats fed control diets. Thus the beneficial effects of a fish oil diet may result from defective immune surveillance and from alterations in eicosanoids.

Topics: Animals; Antibodies, Anti-Idiotypic; Basement Membrane; Dietary Fats, Unsaturated; Dinoprostone; Female; Fish Oils; Immunization, Passive; Immunoglobulin G; Kidney; Kidney Glomerulus; Macrophages; Nephritis; Peritoneal Cavity; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane B2; Tissue Distribution

The value of high polyunsaturated fatty acid (PUFA) diets in preventing diabetic nephropathy in rats was studied. Diabetes was induced by intravenous injection of streptozotocin (SZ), 65 mg/kg. Rats were divided in four groups fed diets containing 11% fat for 38 weeks. Dietary fat derived from four sources: beef tallow (BT; rich in saturated fatty acids), evening primrose oil (EPO; rich in gamma linolenic [GLA] and linoleic acids [LA]), safflower oil (SO; rich in LA), and fish oil (FO; rich in eicosapentaenoic [EPA] and docosahexaenoic [DHA] acids). Ultralente insulin was administered every other day to maintain the blood glucose levels between 11.1 and 22.2 mmol/L (200 and 400 mg/dL). The diets prepared with EPO and SO had a clear beneficial effect on proteinuria, glomerular sclerosis, and tubular abnormalities, as compared with BT. Both diets also increased the ratio of renal cortical production of 6-keto-PGF1 alpha to thromboxane B2 (TXB2), the stable metabolites of PGI2 and TXA2, respectively. They did not induce significant changes in plasma lipid composition. The FO diet did not have an effect on renal disease, but decreased plasma lipids and inhibited eicosanoid synthesis by platelets and kidney cortex. FO feeding was associated with a lowered 6-keto-PGF1 alpha/TXB2 ratio. It is concluded that high LA diets are protective in this model of diabetic nephropathy. The effect may be secondary to modifications of the eicosanoid balance. Diets containing FO have a beneficial effect on plasma lipids in this model.

Topics: Animals; Blood Platelets; Calcium; Cholesterol; Creatinine; Diabetic Nephropathies; Dietary Fats, Unsaturated; Eicosanoids; Female; Kidney; Linoleic Acids; Phospholipids; Phosphorus; Proteinuria; Rats; Rats, Inbred Strains; Serum Albumin; Thromboxane B2; Triglycerides

The mechanisms responsible for hyperfiltration in diabetes mellitus (DM) as well as for the initiation and progression of diabetic nephropathy are not fully elucidated. Enhanced prostaglandin E2 (PGE2) production has been invoked in the former and thromboxane (TXB2) and hyperlipidemia in the latter. Fish oil (FO)-enriched diets can favorably alter eicosanoid synthesis and serum lipid profiles. We therefore examined the effects of a FO-enriched diet on glomerular filtration (GFR), proteinuria, glomerular eicosanoid production, and serum lipids in rats with streptozotocin-induced DM (STZ-DM). Groups of 5-8 rats with STZ-DM were maintained on low insulin and then pair-fed with isocaloric diets enriched with either FO (20% w/w) or beef tallow (BT; 20% w/w). GFR was determined in the same animals at onset of diet and after 8 and 20 weeks on the respective diets by [14C]inulin clearance using implanted osmotic minipumps each time. Significant hyperfiltration was present initially and GFR did not change on either diet for 20 weeks, in spite of a significant and greater than 50% decrease in all prostaglandins (PGE2, TXB2, PGF2 alpha, 6-keto, PGF1 alpha) produced by glomeruli isolated from DM/FO as compared to DM/BT or control rats. FO diet completely corrected the hypertriglyceridemia of diabetes and significantly reduced the mild and early proteinuria of DM. The decrease in proteinuria and the correction of hyperlipidemia of DM by a FO-enriched diet may be beneficial in the long term not only for the development of diabetic glomerulopathy, but also for the accelerated atherosclerosis of DM.

Topics: Animals; Diabetes Mellitus, Experimental; Dinoprostone; Eicosanoids; Female; Fish Oils; Glomerular Filtration Rate; Hyperlipidemias; Kidney; Kidney Glomerulus; Lipids; Lipoproteins; Organ Size; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane B2

There has been no useful treatments for chronic vascular rejection (CVR) after kidney transplantation until now. Recently, however, some reports have suggested that the thromboxane A2 synthetase inhibitor, OKY-046, is useful in reducing proteinuria in nephrotic syndrome and preventing progression of CVR. Five patients with CVR (serum creatinine range: 1.7-2.6 mg/dl) were treated with OKY-046 for over one year and the effect of OKY-046 was evaluated. One patient developed acute rejection and another renal hypertension during this study. Except for the cases of acute rejection and renal hypertension, serum creatinine slightly decreased in 1 case and remained unchanged in 2 cases. Urinary excretion of protein and thromboxane B2 decreased significantly but prostaglandin E2 did not change in the treatment of the deterioration with OKY-046. We concluded that OKY-046 was effective in preventing graft function and decreasing urinary protein excretion in kidney transplant recipients with CVR.

Topics: Acrylates; Chronic Disease; Female; Graft Rejection; Humans; Kidney; Kidney Transplantation; Male; Methacrylates; Prostaglandins E; Proteinuria; Thromboxane B2; Thromboxane-A Synthase

Rats with extensive renal mass reduction develop hypertension, proteinuria and progressive glomerulosclerosis. Previous studies have demonstrated that these changes are associated with an increased urinary excretion of thromboxane compared with normal rats and that the administration of a thromboxane synthetase inhibitor prevents glomerulosclerosis and progressive renal function deterioration. On this basis it has been speculated that the thromboxane synthetase inhibitor, by inhibiting platelet thromboxane, reduces platelet aggregation and prevents the generation of substances that can influence glomerular functional properties. Because the thromboxane synthetase inhibitor also inhibits thromboxane synthesis by resident glomerular cells and lowers blood pressure in these animals, the question of whether platelet thromboxane is indeed the factor implicated in the development of renal disease after renal ablation remains unanswered. To address this issue the authors administered at different time intervals from the surgical procedure a low-dose of oral aspirin (ASA) to rats with remnant kidney. This approach resulted in selective inhibition of platelet cyclooxygenase leading to an almost complete prevention of platelet thromboxane generation. Low-dose ASA spared renal cyclooxygenase as documented by a lack of significant inhibition of glomerular and urinary 6-keto-PGF1 alpha and did not lower blood pressure. Renal function studies showed that low-dose ASA, despite inhibiting platelet aggregation, had no effect on proteinuria and progressive renal insufficiency irrespectively if administered late (ie, 80 days after surgery) and given daily for all the observation period (ie, 20 days) or earlier in the course of the disease (ie, 40 and 10 days after surgery). Histologic data showed that the degree of glomerulosclerosis and tubulo-interstitial damage was not significantly different in rats with reduction of renal mass alone compared with rats with remnant kidney given low-dose ASA. In conclusion, the present findings indicate that inhibition of platelet aggregation and thromboxane formation does not prevent the progressive glomerulosclerosis that develops in rats with surgical reduction of renal mass. It is suggested that the beneficial results obtained previously in the same model by the use of a thromboxane synthesis inhibitor must be attributed either to an effect on resident glomerular cell thromboxane synthesis or to lowering systemic blood pressure.

Topics: Animals; Aspirin; Blood Platelets; Kidney; Kidney Diseases; Kidney Glomerulus; Male; Platelet Aggregation Inhibitors; Prostaglandin-Endoperoxide Synthases; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane B2

The effect of the thromboxane synthesis inhibitor UK 38485 on glomerular filtration rate (GFR) and proteinuria was evaluated in a rat model of unilateral membranous nephropathy. Two and 24 hours following perfusion of kidneys with cationized human IgG and i.v. administration of anti-human IgG-antiserum (in situ ICGN), glomerular thromboxane B2 (TxB2) formation was significantly higher (2 hr: 448 +/- 116 pg/mg protein/min; 24 hr: 173 +/- 21 pg/mg protein/min) compared to control (C) kidneys (2 hr: 173 +/- 21 pg/mg protein/min, P less than 0.005; 24 hr: 154 +/- 17 pg/mg protein/min, P less than 0.025). Two and seven days after induction of ICGN these differences were no longer present. Pretreatment with the thromboxane synthesis inhibitor UK 38485 prevented the decrease in GFR, which occurred two hours after induction of the glomerular disease (without UK: 161 +/- 31; with UK 325 +/- 21 microliters/100 g body wt/min). This UK 38485 effect on GFR was no longer detectable at 24 hours, two days and seven days. Initiation of glomerular immune injury was followed by significant proteinuria which averaged 250 +/- 85 mg/24 hr at day two. UK 38485 treatment, which reduced TxB2 formation in isolated glomeruli by 90% did not influence proteinuria. These data demonstrate that induction of heterologous, in situ immune complex glomerulonephritis stimulates glomerular thromboxane B2 formation, an effect which partially modulates the decrease in GFR at two hours. Thromboxane, however, does not seem to play a role in the mediation of proteinuria in this animal model.

Topics: Animals; Glomerular Filtration Rate; Glomerulonephritis, Membranous; Imidazoles; Proteinuria; Rats; Thromboxane A2; Thromboxane B2; Thromboxane-A Synthase; Time Factors

The effects of alimentary hypercholesterolemia and nephrotic hyperlipidemia, alone and in combination, on rat peritoneal macrophage phagocytosis, basal eicosanoid production, and glomerular macrophage number during peak PA nephrosis were evaluated in rats fed four different diets: 1) normal/standard chow; 2) PA/standard chow; 3) normal/cholesterol-supplemented diet; and 4) PA/cholesterol-supplemented diet. Both PA/standard chow and normal/cholesterol-supplemented rodent groups manifested significantly greater peritoneal macrophage phagocytosis and glomerular macrophage number when compared with normal/standard chow animals. However, the combination of the nephrotic state with superimposed alimentary hypercholesterolemia (PA/cholesterol-supplemented group) produced the greatest rise in these parameters, a rise that was significantly greater than was produced in the three other groups. Regarding basal eicosanoid production by macrophages, there was a numerical trend toward increased production of thromboxane B2 in the PA/standard chow animals and normal/cholesterol-supplemented rats when compared with normal/standard chow. Again, the combination of nephrosis and alimentary hypercholesterolemia in the PA/cholesterol-supplemented group was associated with a significantly greater amount of thromboxane B2 generated when compared with the other three groups. Regarding PGE2 production, there were no significant differences among the groups, despite marked differences in fasting serum lipid levels. This data suggest that there is a synergistic effect between alimentary hypercholesterolemia and the secondary hyperlipidemia of nephrosis in producing these macrophage functional alterations. Because fasting triglyceride values between the two nephrotic groups were indifferent, one can further speculate that it is the elevation of the serum cholesterol value that predominantly evokes these changes in macrophage function.

Topics: Animals; Cell Count; Cholesterol; Dinoprostone; Eicosanoids; Hypercholesterolemia; Hyperlipidemias; Kidney Glomerulus; Macrophages; Male; Nephrosis; Nucleosides; Peritoneal Cavity; Phagocytosis; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane B2; Triglycerides

Tumor necrosis factor (TNF) is a polypeptide hormone produced by activated macrophages detectable in the circulation of experimental animals given endotoxin. Recent evidence strongly suggests that many of the deleterious effects of endotoxin in experimental animals are mediated by TNF. Because endotoxemia in experimental animals and humans is associated with glomerular damage the present investigation was designed to establish whether TNF directly induces glomerular functional and structural changes. Twenty-three rabbits were given human recombinant TNF at the doses of 0.08, 0.8, and 8.0 micrograms/kg/h as a continuous 5-hour intravenous infusion. Animals were killed at the end of the infusion. All rabbits given 0.8 and 8.0 micrograms/kg/h TNF developed anemia (Ht value decrease at 5 hours: 0.8 microgram/kg/h, 15%; 8.0 micrograms/kg/h, 16%); leukopenia (leukocyte count decrease at 5 hours: 0.8 micrograms/kg/h, 47%; 8.0 micrograms/kg/h, 59%); thrombocytopenia (platelet count decrease at 5 hours; 0.8 micrograms/kg/h, 45%; 8.0 micrograms/kg/h, 57%). Rabbits given 8.0 micrograms/kg/h also had renal failure (serum creatinine from 1.02 +/- 0.15 to 1.64 +/- 0.34 mg/dl). By light microscopy only occasional polymorphonuclear leukocytes in the glomerular capillaries were detectable in rabbits infused with 0.08 micrograms/kg/h TNF, whereas with 0.8 micrograms/kg/h TNF the presence of inflammatory cells in the glomerular capillaries was the prominent finding. With 8.0 micrograms/kg/h TNF beside leukocyte accumulation, fibrin was detected in the glomerular capillary lumens of two of eight animals. Electron microscopy found dose-dependent glomerular endothelial cell damage in animals given TNF with fibrinlike material in the capillary lumens. Glomerular changes induced by TNF were remarkably similar to those previously found in animals given endotoxin. Thus, TNF is likely to be the mediator of endotoxin-induced glomerular damage and can be regarded as a new mediator of macrophage-dependent damage in glomerulonephritis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Creatinine; Kidney; Kidney Glomerulus; Male; Microscopy, Electron; Proteinuria; Rabbits; Regional Blood Flow; Thromboxane B2; Tumor Necrosis Factor-alpha

Recent studies have suggested a role for thromboxane in the progression of renal disease. The current study evaluated the role of this arachidonic acid metabolite in a model of renal disease which bears many biologic similarities to that in the kidneys of patients with chronic progressive renal failure. The model is that induced by ferritin-anti-ferritin immune complex nephritis in Dahl-salt sensitive rats rendered hypertensive by a high salt intake. Rats with this model of renal disease were chronically given a thromboxane synthetase antagonist OKY-046 or a placebo treatment from 16 to 29 weeks of age. Sequential observations of serum creatinine and 24-hour urinary protein excretion showed an ameliorating effect of OKY-046 on these renal parameters. Histologic examination of the kidneys also showed significantly less glomerular sclerosis in OKY-046 treated animals. The efficacy of OKY-046 was monitored by measurements of serum TXB2 levels and of glomerular production of TXB2 (and other prostaglandins); amounts of TXB2 were significantly reduced in the OKY-046 group. It is concluded that blockade of thromboxane generation has been successful in ameliorating the functional and structural lesions in this model of renal disease, providing further support to the thesis that thromboxane is an important mediator in events leading to eventual chronic renal failure and sclerosis.

Topics: Acrylates; Animals; Creatinine; Fatty Acids, Unsaturated; Immune Complex Diseases; In Vitro Techniques; Kidney Glomerulus; Male; Methacrylates; Nephritis; Proteinuria; Rats; Thromboxane B2; Thromboxane-A Synthase; Thromboxanes

Topics: Animals; Blood Pressure; Diabetes Mellitus, Experimental; Kidney; Male; Methacrylates; Proteinuria; Rats; Rats, Inbred Strains; Renin; Thromboxane A2; Thromboxane B2; Thromboxane-A Synthase

To determine if a selective thromboxane (TX)A2 synthetase inhibitor is clinically effective for the treatment of nephrotic syndrome, 11 patients with nephrotic syndrome were treated only with OKY-046, (E)-3-4-(1-imidazolylmethyl)phenyl-2-propenoic acid hydrochloride monohydrate, for at least 8 weeks. Urinary excretion of protein, TXB2, 2,3-dinor-TXB2, and beta-N-acetyl-D-glucosaminidase decreased with OKY-046. Creatinine clearance value, and urinary excretion of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), however, did not show any significant change, while serum albumin level increased. Two patients with minimal change nephrotic syndrome showed complete remission only with OKY-046. These results demonstrate that the selective TXA2 synthetase inhibitor is an effective drug for the treatment of chronic glomerulonephritis accompanied by nephrotic syndrome.

Topics: 6-Ketoprostaglandin F1 alpha; Acrylates; Adolescent; Adult; Aged; Female; Glomerulonephritis; Humans; Male; Methacrylates; Middle Aged; Nephrosis, Lipoid; Nephrotic Syndrome; Proteinuria; Thromboxane B2; Thromboxane-A Synthase

We prospectively evaluated a platelet-inhibitor regimen of dipyridamole and aspirin in 28 patients with insulin-dependent diabetes mellitus and well-established nephropathy. After a mean treatment period of 4.3 years, iothalamate clearance (Ciot) was reasonably well maintained and urinary protein excretion was reduced in 7 patients (25%), whereas 21 (75%) had progressive nephropathy. Analysis of outcome revealed that all 7 patients with stable nephropathy and 9 of the 21 with progressive disease had baseline Ciot values that exceeded 50 ml/min per 1.73 m2. Shortened platelet survival improved after 3 months of treatment, and the distribution between patients who had stable and those who had progressive disease was approximately equal. Mean changes in fasting plasma glucose level, glycosylated hemoglobin, and blood pressure did not differ between these two groups. In a short-term protocol, urinary protein and thromboxane B2 significantly declined, whereas variable urinary levels of prostaglandin E2, 6-ketoprostaglandin F1 alpha, and Ciot did not change after 3 months of treatment with dipyridamole and aspirin. These findings suggest that treatment with dipyridamole and aspirin may stabilize renal function by reducing platelet hypersensitivity and production of thromboxanes by platelet or renal tissue (or both). In turn, constrictor activity in the glomerular vessels, mesangial contractility, and glomerular membrane permeability are decreased. These data also add evidence in support of a role for thromboxane A2 in the pathogenesis of experimental and human glomerular disease.

Topics: Adult; Aspirin; Blood Platelets; Cell Survival; Creatinine; Diabetic Nephropathies; Dipyridamole; Drug Therapy, Combination; Female; Humans; Iothalamic Acid; Male; Middle Aged; Platelet Aggregation Inhibitors; Prospective Studies; Proteinuria; Thromboxane B2

One hundred NZB/W F1 female mice were studied to compare the effects of a thromboxane synthase inhibitor (TSI), a stable prostacyclin analog (iloprost) and prostaglandin E1 (PGE1) in the evolution of the nephritis. At 10 weeks of age mice were randomly assigned to cohorts of 20 to receive either no treatment, vehicle control, PGE1, iloprost or TSI. Proteinuria, mortality, systemic blood pressure, renal immune complex deposition, urinary TX B2 and 6 keto PGF1 alpha levels were measured. Mice receiving PGE1 and iloprost had a significant delay in the onset of proteinuria and reduction in mortality at 40 weeks. The TSI treatment had no apparent effect on proteinuria or mortality. The amelioration of the nephritis was not associated with an alteration in immune complex deposition in survivors at 40 weeks. Although PGE1 and iloprost lessened the age related increase in urinary TX B2, increased the urinary 6 keto PGF1 alpha levels and the ratio of 6 keto PGF1 alpha to TX B2; so did the TSI. The PGE1 treated mice did experience a marked and persistent reduction in blood pressure but this was not observed in the iloprost- or the TSI-treated mice. All drugs tested reduced the age-related increase in thromboxane B2 but only the PGE1 and iloprost had a significant effect on the evolution of the nephritis.

Topics: 6-Ketoprostaglandin F1 alpha; Age Factors; Alprostadil; Animals; Benzofurans; Blood Pressure; Disease Models, Animal; Epoprostenol; Female; Iloprost; Lupus Nephritis; Mice; Mice, Inbred NZB; Mice, Inbred Strains; Nephritis; Proteinuria; Thromboxane B2; Vasodilator Agents

Indomethacin has been used to lower proteinuria in human glomerular diseases with controversial results. The mechanism of indomethacin beneficial effects has not been established. A possible explanation is that indomethacin reduces proteinuria by inhibiting the synthesis of renal prostaglandins (PGs); however, appropriate studies to address this issue have never been done. The objectives of the present study were: to investigate whether indomethacin influences protein excretion in an experimental model of immunologically-mediated glomerular disease; to establish if the possible favorable effect of indomethacin on proteinuria is related to a reduction in glomerular filtration rate (GFR); to establish the possible association between the antiproteinuric effect of indomethacin and its inhibitory effect on arachidonic acid (AA) metabolites of renal or extrarenal origin; and to further investigate the relationship between proteinuria and renal thromboxane (Tx) synthesis previously demonstrated in experimental models of nephrotoxic nephritis and adriamycin (ADR) nephrosis. To this purpose we used an experimental immune-complex disease, passive Heymann nephritis (PHN) which was induced in the rat by a single intravenous (i.v.) injection of heterologous serum directed against a brush border component (gp 330 antigen). Indomethacin at a dose of 6 mg/kg intraperitoneally (i.p.) administered for four consecutive days to PHN animals during the period of heavy proteinuria, effectively reduced urinary protein excretion. The reduction in proteinuria does not appear to be a consequence of a reduction in GFR as documented by inulin clearance. Glomerular synthesis and urinary excretion of vasodilatory prostacyclin (PGI2) and PGE2 were decreased or unchanged in PHN animals in respect to control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Dinoprostone; Glomerulonephritis; Imidazoles; Immune Complex Diseases; In Vitro Techniques; Indomethacin; Kidney Function Tests; Kidney Glomerulus; Male; Microvilli; Prostaglandins E; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane B2; Time Factors

The membrane attack complex (MAC) of complement (C) has been shown to stimulate prostaglandin (PG) and thromboxane (Tx) synthesis in nucleated cells. Because glomerular epithelial cell injury and altered permeability in rat membranous nephropathy are mediated by the MAC, the authors examined whether MAC-induced proteinuria is linked to glomerular prostanoid synthesis. In kidneys containing non-nephritogenic, non-C-fixing gamma 2 sheep anti-Fx1A (planted antigen) that were perfused in vitro with C-fixing guinea pig anti-sheep IgG and a C source (fresh human plasma, 50% vol/vol in buffered bovine albumin), heavy proteinuria developed, reaching 4.27 +/- 1.20 mg/min/g at 100-120 minutes (n = 8). Cyclooxygenase blockade with 10(-4) M indomethacin (n = 6) inhibited urinary PGE2 excretion (569 +/- 47 to 124 +/- 18 pg/min/g, P less than 0.001) and lowered proteinuria (1.06 +/- 0.42 mg/min/g, P less than 0.001). Reduced protein excretion (0.88 +/- 0.12 mg/min/g, n = 6, P less than 0.001) also occurred with inhibition of Tx synthetase by OKY-046, 10(-4) M, a dose that was shown in separate perfusions to inhibit urinary TxB2 excretion by greater than 85%. Control kidneys, without planted antigen and perfused with anti-sheep IgG and plasma, excreted 0.30 +/- 0.05 mg protein/min/g (n = 6). Because inulin clearance was reduced by indomethacin, renal hemodynamic factors may have contributed to the reduction in proteinuria observed with this drug. However, insulin clearance was not significantly affected by OKY-046, implying that inhibition of Tx synthetase reduced proteinuria independently of changes in renal hemodynamics. Thus, proteinuria in rat membranous nephropathy is due to MAC-dependent glomerular epithelial injury and is mediated, in part, by Tx.

Topics: Animals; Cell Membrane Permeability; Complement Membrane Attack Complex; Complement System Proteins; Cricetinae; Cyclooxygenase Inhibitors; Dinoprostone; Hemodynamics; Indomethacin; Inulin; Kidney; Kidney Glomerulus; Prostaglandins E; Proteinuria; Thromboxane B2; Thromboxanes

The effects of increasing two dietary polyunsaturated fatty acids, eicosapentaenoic and linoleic, on the glomerulonephritis induced by repeated injections of apoferritin in the mouse were studied. Urinary protein excretion was measured serially; serum creatinine, aortic and renal production of eicosanoids and kidney histology were measured at sacrifice at 8 weeks. Both high EPA and LA feedings were associated with lesser proteinuria, normalization of renal function and profound changes in the tissue production of prostaglandin and thromboxane, which may explain their protective effect in this model of renal disease.

Topics: Animals; Apoferritins; Creatinine; Dietary Fats; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Glomerulonephritis; Immune Complex Diseases; Linoleic Acid; Linoleic Acids; Male; Mice; Prostaglandins; Proteinuria; Thromboxane B2

To determine whether the amount of cyclooxygenase metabolites correlates with the development of lupus nephritis, intrarenal eicosanoid production was measured in autoimmune mice. Disease progression was related to the renal biosynthesis of prostaglandin (PGE2), prostacyclin (6 keto PGF1 alpha), and thromboxane (TXB2) using the MRL-lpr and NZB X NZW F1 hybrid mouse strains with predictably progressive forms of renal disease that mimic the human illness. Mice were evaluated for renal disease by measuring urinary protein excretion and renal immunopathological conditions and these features were related to renal eicosanoid production. These studies show that: (a) intrarenal synthesis of TXB2 increased incrementally in MRL-lpr and NZB X NZW F1 hybrid mice as renal function deteriorated and renal pathologic events progressed; (b) there were no consistent increases in the levels of two other cyclooxygenase metabolites, PGE2 or 6 keto PGF1 alpha; (c) increased TXB2 production occurred in the renal medulla, cortex, and within enriched preparations of cortical glomeruli; (d) when renal disease was prevented by pharmacologic doses of PGE2, intrarenal TXB2 did not increase; (e) administration of a dose of ibuprofen (9 mg/kg), a cyclooxygenase inhibitor capable of reducing 90% of platelet TXB2 without affecting intrarenal levels, did not retard the progression of renal damage. Taken together, these data indicate that the intrarenal level of TXB2 rises in relation to the severity of murine lupus nephritis. Furthermore, because of the potential deleterious effects of TXA2, enhanced production of this eicosanoid may be an important mediator of renal injury.

Topics: Animals; Dinoprostone; Female; Glomerulonephritis; Ibuprofen; Kidney; Kidney Glomerulus; Lupus Erythematosus, Systemic; Male; Mice; Mice, Inbred NZB; Prostaglandins E; Prostaglandins F; Proteinuria; Species Specificity; Thromboxane B2

Dietary supplementation of fish oil as the exclusive source of lipid suppresses autoimmune lupus in MRL-lpr mice. This marine oil diet decreases the lymphoid hyperplasia regulated by the lpr gene, prevents an increase in macrophage surface Ia expression, reduces the formation of circulating retroviral gp70 immune complexes, delays the onset of renal disease, and prolongs survival. We show that a fatty acid component uniquely present in fish oil but not in vegetable oil decreases the quantity of dienoic prostaglandin E, thromboxane B, and prostacyclin normally synthesized by multiple tissues, including kidney, lung, and macrophages, and promotes the synthesis of small amounts of trienoic prostaglandin in autoimmune mice. We suggest that this change in endogenous cyclooxygenase metabolite synthesis directly suppresses immunologic and/or inflammatory mediators of murine lupus.

Topics: Animals; Dinoprostone; Fatty Acids, Unsaturated; Female; Fish Oils; Histocompatibility Antigens Class II; Humans; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Lymphocyte Activation; Macrophages; Male; Mice; Mice, Mutant Strains; Oils; Prostaglandin-Endoperoxide Synthases; Prostaglandins E; Proteinuria; Safflower Oil; Thromboxane B2

Altered glomerular metabolism of arachidonic acid (AA) has already been demonstrated in experimental nephrotoxic nephritis. The enhanced synthesis of thromboxane A2 (TxA2) in isolated glomeruli that has been found may mediate changes in renal hemodynamics. The objectives of this investigation were: to check whether glomerular AA metabolism is also altered in a model of glomerulopathy in which no leukocyte infiltration or platelet deposition could be demonstrated; to establish a correlation between the altered AA metabolism and proteinuria; and to explore whether the alteration of the prostaglandin (PG) pathway found in isolated glomeruli is an in vitro artifact or reflects a modification in vivo. We used a model of glomerular damage characterized by heavy and persistent proteinuria, which was induced in the rat by a single intravenous injection of adriamycin. At light microscopy, minimal glomerular abnormalities were found in this model. Electron microscopy showed profound alterations of glomerular epithelial cells with extensive fusion of foot processes and signs of epithelial cell activation. Electron microscopy of numerous glomeruli showed no platelet deposition or macrophage and leukocyte infiltration in this model. Isolated glomeruli from nephrotic rats studied 14 or 30 d after a single intravenous injection of adriamycin (7.5 mg/kg) when animals were heavily proteinuric generated significantly more TxB2, the stable breakdown product of TxA2, than normal glomeruli. No significant changes were found in the other major AA metabolites formed through cyclooxygenase. Urinary excretion of immunoreactive TxB2 was also significantly higher in nephrotic than in normal animals. Administration of a selective Tx synthetase inhibitor, UK-38,485, from day 14 to day 18 after adriamycin resulted in a significant reduction of proteinuria compared with pretreatment values. Glomerular synthesis and urinary excretion of TxB2 were normal during the UK-38,485 treatment. Additional experiments showed that elevated glomerular synthesis and urinary excretion of TxB2 were not a consequence of increased substrate availability. Maximal stimulation of the renin-angiotensin axis with furosemide increased glomerular TxB2 synthesis in normal rats, which was significantly lower than in nephrotic animals. Finally, experiments using a unilateral model of adriamycin nephrosis indicated that the enhancement of glomerular TxB2 synthesis is not simply a consequence of the nephrotic syndro

Topics: Animals; Blood Platelets; Doxorubicin; Imidazoles; Kidney; Kidney Glomerulus; Male; Nephrosis; Prostaglandins; Proteinuria; Rats; Rats, Inbred Strains; Sulindac; Thromboxane B2; Thromboxane-A Synthase; Thromboxanes; Time Factors

Topics: Alprostadil; Animals; Antibodies, Antinuclear; Antigen-Antibody Complex; Cyclooxygenase Inhibitors; DNA; Female; Ibuprofen; Kidney Glomerulus; Lupus Erythematosus, Systemic; Mice; Mice, Inbred NZB; Prostaglandin Antagonists; Prostaglandins E; Proteinuria; Thromboxane B2